Apparatus for indirectly laying antiaircraft guns



s SEARCH Room 1,615,509 CROSS REFERENC 192?. E MM5@ W.F.GROTENDORST APPARATUS FOR INDIRECTLY LAYING ANTIAIHCRFT GUNS 2 Sheets-Sheet l Original Filed March 29, 192

jan. EJZ?. LGSQ W. F. GROTENDORST I l APPARATUS FOR NDIRECTLY LAYING ANTIAIRGRAFT GUNS Original Filed March 29, 1926 2 Sheets-511961l 2 jgxt.

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i ,ki/fg, .M /f f u g Y a Patented dan. 25', i927.

'WILLEM FRETJER-IK GROEJENDURST, OF HELDER, NETHERLANDS.

Original application lcf March 29, '1926, Serial Divided and this application filed This application is a division ot' mycopending application Serial No. 98,3%, tiled March fit), 1926. y

This invention relates to apparatus for indirectly laying anti-aircratt guns ot the type wherein data obtained troni observations taken at points distant troni the gun are transformed into data referring to the position ot the gun.

'this invention has lor its object to provide a device whereby such transformation ot' data can be immediattlf,T and easily performed.

ri`he present invention consists in an iniprored device tor the laying ot anti-aircraft guns, in which two charts are pirotallY connected together7 each chart having a ruler associated therewitl, the charts and rulers being adapted to he set With the position ot the ruler on one chart dependent upon the setting of the rulcr on the other chart, and so that upon one ot the cl rts will he represented. the projections of the target, the observation post and the gun upon a horizontal plane, While upon the other chart will be represented the relation ot the target and the gun with reference to the vertical plane through both.

The invention is illustrated in the accoinpanying drawings in some ot its e1nbodiments.

Fig. l shows in perspective the mutual relations between the observation post, the gun and the aircraft at two diterent nioments.

l 2 diagramma if-allT shows an apparatus with three rulers pirotalile about a common point which is used tor indirectly laying anti-aircraft guns.

3 is a diagranin'iatic representation ot the observation and gun posit-ions, showing the gun as oriented alter the initial observation.

Figure t is a top rien* ot' the apparatus indicated diagraminaticallpi in Figure 2.

Figure. 5 shows the graduated 'ring at the gun.

Figure G shows a .special torni ot one. ot the. rulers.

Figure 'i shows di rraininaticalliv a inodilicatii'in in which the Alorenients ol the rulers are f lutoumt:ir-all;- dcneudent on' one another.

ln Fig. l. li indicates the place at which the gun is mounted, l the observation post 'rom which the aeroplune or other aircraft o. 93,324, and in the Netherlands November 19, 1923. Aug-)11st 7, 1928. Serial No. 127,951.

V1, is observed, and V2 the required pointo't impact, i. e. the meeting point ot aerof plane and projectile. A and B are the projections of V1 and V2 respectively on the horizontal plane through P and K. The target is assumed to move at a constant altitude. ln order to be able tovhit thevaeropiane tiring troni K to -V2, it is necessary to have the following data:

(1).'l`he angle 'D3-lthe angle of super elevation:

The angle D3; V2KB, as indicated in the drawing.

(2) The angle z indicating the direction ot KB with regard to 'a fixed direction. it preferable to use for this fixed direc tion the direction PK, as shown in the drawing.

(3) The timing of the fuse.

Figure diagrannnatically indicates a top vieu ot an apparatus tor use with antiaircrat't guns. iilllAQ indicates a iXed lino on a lixed sector GAQC whose centre is lll. Si@ is so positioned that 4 oMa2= nel: APK of Figure l, MA1 corresponding with the distance PA ot Figure l. Through A1 the line Alli) is drawn parallel with the line MG and ot such length as to represent to a sclectpldscale the distance PK of Figure l. {ence )fili corresponds with KA and AZME with P1= Pelli Then EF is drawn at rightangles to ME, and BF2-7L ot Figure l, 7L being the height of the aeroplane :VALL-V213. ME and MF are extended to meet the outside circumference at Gr and H. Then MFzKVl and zupposing that the aeroplane is stationary at VT in this way the data are obtained ior hitting V1 from li. By the aid of [311 Pb D2 and distance MF which corresponds to HV1 the gun may be given the required vertical and lateral direction as well as the necessary tuze setting. vOt" course, the angle of super elevation inust be added to D? In Figure 3, P and K indicate the centres of the horizontal graduations ot the instruments tor measuring angles and distancees at the. observation post and at the gun. "these graduations are oriented so that the OO-lSOO graduations correspond with the connecting line Pl. Il on the graduation of the gun lil is marked out, 'for example., by means of an indicatifr Q, it is necessary, in order to train the gun upon V1, to mark out the angle l.1 with reference to O.

All corrections relating` to the lateral direction may be easilge;"-rted by not rcading l?1 (Figure i.) at G but upon a dis` placeable indicator Tf1 adjusted with rel'erence to G so as to correct `tor the sum of all lateral corrections.

B5' this means the difference between the angles AKP, BHP, X'll) may be corrected mechanically.

The longitudinal corrections may also be made simultancoush` by arranging upon MG a displaceable scale lV.: which bears the range `giaduations7 and which is adjusted with reference to the point E of the lineAlE so as to allow for the sum ot all range corrections. By this means the dit- ;tercnce between the distance AK and BK may be corrected mechanically. if' non El" is set; 'upon the last-mentioned indicator W2, then D2 and MF are corrected in the proper proportion. while by adjusting another indicator d'3 with reference tO the point El. so as to allow for the angle ot' super elevation, then the angle D3 the angle ol' super elevation may immediately be read. By marl e' out at the gun the cor- Accted :ii-.gie EF1 e is laterallyy directed to V2, and by applV ing l)3 the angle of super eleva-ion the gun is also laid on V2 as regards the height.. The timing is also linon'n from the corrected KVI.

Figure l shows the apparatus as it may be constructed for use. However, this is 01115v a construetional example which may be modii'ied in details.

The rulers L1, L2, and L1. are pivotalljv mounted at the centre M ot' the chart on the surface 01' which a fixed radial line MA is drawn and graduated from the point M to a selected scale, millimeters, tor instance, representing meters. 'lfhe periphery of the chart is zlso graduated in degrees and minutes in each direction from the line Mill. The ruler Ll is read on the left part of the periphery1 of the chart where the graduations run towart-.s the lett from OO-lSOO. This ruler corresponds with MC or" Figure Q.. The ruler l.,2 corresponding With HG ot Figure 2 is read on the righthand halt of the periphm5v ot' the chart. Where the graduations run to the right, said graduations beingl in deg-rees and minutes. The ruler L3 Correspendingr with MH of Figure 2 is read linall.' on a -le haring g a'duatiens from (lO-90"D and marked on the peripheif.7 ot a quadrant S which is 'formed in one with the ru i L.. and therefore retates with this ruler. The various rulers in so tar as may ne necessary are provided with means :for making;- the corrections. the ruler L1 itsell'4 distance l-eraduations are provided, while to the lower part ot the ruler and rotatint,r with it an arc-shaped part Bl is formed on which divisions in thousandth parts are provided both to the right and to the lett ytroni a zero-point. Furt ici-more, a compass cz rd W is .fixed to the ruler L1 und rotates with the said ruler so that ai'ter being once adjusted it always gives the correct indication ot the lateral direction. This is because the ruler L2 which indicates the direction to Which tiring should talle place (ct. Figures 1 and '2) then always comes to the correct point oit' the compass card, and may be provided with a small indicator 'for easy reading.

The ruler L2 is provided n'ith'a scale in the forni of a longitudinallVY displaceable ruler which is graduated in the saine Way as the fixed line MA. 'lfhe construction permits ot' makina' the ruler Yerv narrow. which is necessary tio obtain a. convenient(design which shall allow for a small height ot the aircraft target. 0n the right-aand side of the ruler Lg a. number ot distance graduations are provided increasing both aboi'e and below a zero-point, and the displaceable ruler 3G carries an index which may be set to correspond -with a desired number ot' 7 bij gliding* the, (li-j" iiicrtulila". 36 along the ruler L2, and by this means longitudinal corrections may be eii'ccted. This arrangement corresponds with the displat-cable indicator Tiri ot Fig. '2.

The ruler L2 has atits lower end a lined arcuate part B2, similar to that ot the ruler L1. lThe arcuate part ll2 is subdivided into an upper halt and a lon'er hal-l'. the upper half being provided on both sides ot its zero-point with lgraduations in thousandth parts or other suitable units. by which eraduations an ii'idicator Vfl which slidablj,r mounted in said arcuate part B2 mayv be ser to impart lateral correction. 'i he lower half of the arcuate part B2 is also provided with graduations in thousandth parts or other suitable units, from which lateral cor! rections may be read.

A quadrant A. or .sector part F5 is fixed to the ruler L2 and is provided with data indicating:

(l) The tangent of the angle o .supereleration that is the angle between the line of sight and the line o'r tire, for various angles of elevation: and various ranges; the ratio o't' the sum of lost time and time o? flight to th time lzetu'een tra-o observations:

The ning or fus-e setting For 'vm-ique angles otl elevation and ranges.

il-.Then the ruler l... is set at the correct la with 'getm'm'we to tlm ruler il.; fluir. each point ot the ruler L3 corresponds to a particular value of the required angle (Di.)

n Uli lllf) lll) rename and the required distance. so that to each point ot the sector belong special data, which must he indicated on it.

The ruler L.: is provided similar-l5v to the l'ixed line und the ruler L2, with `gradualions imlicatiue distances of Q5 metres. rlhe lower end of Ll; is provided with an arcuate part ll., extending only to the right, with graduations mai-lied to the rigi'ht 'troni a Zero-poilu'. on which the angle ot super elevation ma;v be set by the aid of the slidahe indicator *WT It then the `graduation o'l` the periphem7 of the sector f5 is read. at ll'm then the sum ot the required angle oi sight and the angle of super elevation is immediately obtained;

In the apparatus o't Figure Ll a number of lines are drawn parallel and to the left 0i the fixed line MA at short intervals and for the salte ot clearness are preferabljv alternatebv black and red. These lines are here used for setting the loose ruler LL parallel Wit-h the ruler L, as hereinafter explained. The ruler` A24-has preferably the form as shown in plan rie-W in Figure The points 3T., S8 and 39 ot ne ruler are in e straight line. The distance 37---38 is arbitrary, the distance SSWD being' on the selected reduced scale equal to trie distance from the observation postl to the gun. On the ruler lil a part from the centre equal in length lo that between points fill' and clearly indicated for instance, hy making' it another color. The length between points 38 and 39 ot the ruler L1. mrstl he adjustable -invordcr that it may he. possible to use the apparatus for various distances between the observation post and the `gun. At. the point 38 a recess or an opening is made in the ruler, in order to be able to read through it the divisions on the tixec line and to be able to adjust the point 3S on these divisions.

Finally in the apparatus shown in Figure Ll a fifth ruler or pin L5 provided hy means ot which the distance IGF ot Figure Q ma;v he marked out. Since is the n'ieasured height of the aeroplane, the ruler L5 must he of extensible torni and preteralgily formed ot telescoping parts, The arrangement is such that the. cent-re line of L is always perpendicular lo the ruler L2 (see Figure 2). For this purpose L5 is substantiall iY a 'l'- square with an extremelyrv small guiding part ll-O hy means oi which the ruler L; can he displaced along' the ruler ln and maintain its perpendicular relation thereto. rl`he line perpeiulieular to L2 and passingr through the point il oic L5. and through the ,guide part l0, must :nso pass through the point` of l), (sce Figure flfhe manipulation ot the apparatus shown in'l'igure @l corileronds in principle with that or the apparatus ot Figure 2. At the oiiservai'fon post the observer begins bj,- olisci\'in j at a certain moment the height und the dis t @aeroplane as as oi Figi. el by moving the ruler L1 to the left from lill-X. '.lheu the ruler L l is laid parallel to lil h r setting the point fin' at the measured distance corresponding to PA (Figure l) ou the lined line )lL-i and by placing the point all on the parallel line going' through the cud ot' the part ot lil which has a distinctive color. Then the ruler L2 is set to abut against t 'ie pointJ 39 ot the ruler L4. and the ruler L5 set to the measured l'ieighty ot the aeroiiilane is placed against L2, opposite to the point 39. after which the ruler L.; is set, to abut against the point 41 of the ruler 3. At Viz and Vf, (both still assumed to he ser at zero) the data maj;v be read corresponding' to the pointl'v1 ot Figure l. These data are required -for finding the necessamv corrections a'tfter -the second mersurement The second olrserration takes place :t'or instance lO seconds later, at which time other data are found which are read at l and. YY1; and on the auxiliaryv ruler 35. Non* the corrections muy he made, for which purpose use made ot the dat-a indicated ou the scctor where he weint ll is now positioned. 'l'he anxiliz'lrj; ruler 3F adjusted to aliou for the increase or decrease in the horizontal distance i'rou'i the n'un to the target during" the lost time plus the time ot flight computed Ytrom the change ot such distance during; the ten seconds interval between ohserrations.

Before the start of the tiring', the total amount ot the turther longitul'linal corrections has preriouslf,Y been determined. namely the corrections due to height of the barometer. n'ind, teniperature of the gnnporfder, and linon'n range difference for the whole battery. This total correction is then also imparted by means of the ruler 36. During the tiring` ot' course this ruler is also used to `:rive the correction due to the Vertical distance through which the projectiles tall during their ilight.

The correction tor the angle oi super elevation is imparted bj.' means of lVS. The lateral cor 'ections are eil'ected as tollowsz By the aid o?" the r r L1 there determined the lateral angular disljilacement of the target during the time between sin'ces-A sive measurenients. rThis may he none mechanicall;v bj.' setting' an indicator lll; to marl; the position ot' the ruler L, during;` the first measureiuent and then rcadineY ai the second measurement the graduation ot the arcuate part B1 which is opposite to TK... The index arrow on the inner end Oi? the ruler 'L2 comes opposite a number on th compass card which indicates the direction lateral displzuenunit determined by inea ot L, the fuieralor now' imaiefliatcly rca ironl a card sphinx (which may be niadc in a very simple waff) the tozzl :1u-munt ol' all lateral correction.: (i. e. correction lior de fiecton dieplacerent ot the target. and wind)T which au... .-:l to liz. 'lo this total amount, however. :hust he added the parallax increase or decrea, i. e. the difference in reading' el L between two measurements and then the whole must be multiplied by the ratio ot the luist time plus time oil flight t the ti' e between two ohserrations? which ratio s directljg1 obtained by reading the sector S. The reerilting Iinal correction is imparted by the indicator lill. Thisl method ot' imparting; correctione inafv he carried .out withinthe time between successive observations or ineaeurenients. lll is a displaceahle indicator carried by the fixed chart'and provided in order to indicate the increase or decrease ot parallax between two obserratione. The angle read on the periphery ot sector S as indicati/tl by lilla and the angle read on the periphery ot the fixed chart as indicated by lill are coiniuunicated to the gun potition, as well as the tiniinaj which is read on the sector S, it' time im .Sed or the c" Lance read on the ruler L2. 'll he gunner is then in posees- Sion of all neceeary data and the gun ina be fired. After the Second meas ire-nient all necessary data may therefore be directly read 'troni the appz'iratus. A3 the correctiong chang-e gradually the turther detern'iii ation ot them is easy.

lt is ad 'isable to arrange the graduated 4. ilu

rin at the gun an( the batteriv telescope in the way indicated in Figure 5, i. e. in two parts each running 'troni O-lS/Oo in opposite directions. lt the graduationfJ should run from 0 to 360 the. ruler L? would be brought beyond the fixed line HJ.. as soon as the aerolilane pasa-cs the vertical plane going` through the orientiup l ne PK, which would malte the reading oi. 1e other parte of the appar-etuis more dzlicult. But with the graduationa arranged as in Fiat 5 all corrections read with the execution o'i the correction 'tor defie-ction and th rection for the wint runat reverse S fuse aa .fjoon the l u the plane in ur ti nn and thml the-al1 tion oi" the correr-Lione can he e other -ide nl the zero-gn,... the co tables being czllcnlated to allow for ri Thus as soon as the aeroplane ha.Q passed the plane in question. tle other `radnations are use/l at the aan. und the other tahles are Reed at the rron'xputingj apparatua. lilith a riewto allowing this. it. ie adrisable to indi'- rename cate all of one Setot corrections; in black and the counter-corrections in red.

lt the battery is at the lett ot the obser- 'ation post the saine apparatus may be used. provided care taken that the Zerwpoint of the graduated riin of the gun on the saine side of' the run as the olcrration po.--'t.

'l`he fixed line oi the appa atari need not curr-espinal with the direction l'ron'i the observation post to the gun. lt another fixed line is taken, e. a certain magnetic bearing'. it is only necessary to give to the ruler L, another lforin as, Jfor example, that indicated in Figure (S. l'he points 37', 3S and B9 inuet then be adjusted on a reduced scale in agreement with the relations existing in reality, lor which purpose the ruler inust be provided with three extensible points.

An innuortant. siinpliiication in the manipulation ot' the apparatus may he etiected by making the niorcnient oi the movable parts automatically dependent on each other. Such a device is indicated by way oit e..\;- ample in Figure T. In this device. the ruler Li is so connected with the ruler Ll, that when disglacing the ruler L1 the ruler L4 is diplaced parallel w'th L1 and the point always reniaine4 on the lined line. For this purpose the ruler L1 is c by two rods :l2 and J3 with an auxiliary ruhr 4S). in which the connections are such that lil. ii-i and i9 'torni a parallelogi'rzun,

iu means ot pivot conuecliona i-i.. l5.

ll-3 aid il nay carry out parallelen-rain nr'nenients. rlhe. rods` l2 and il are parallel to the li'xed line, and ach haI a Slot running' in the longitudinal direction. in which slot guiding pini 5U and 5l of the ruler L L are guided.

l`hen the niorenient ot L.. always remains parallel. to L1. so that 'it Ll ad'ueted on L has onlr to be 1 l adjusted to place. the point on the measured distance PA (Figure l).

liutherniore the point 259 of the ruler L; pivotally connect-ed 'yith the ruler L3, the latter being slidably mounted on L \.='oreo\'er a resilient connection may be proyided between L., and in', so that the rulers gli. La, L2 and L z are automatically lnfoujg'ht `n their correct positions when L, ie set and the point 38 o'll 'l'. brought to the correct place on the fixed line. All data nay he directly read. whereby the lost time may be conside'ably dimiuiahefl` and the nurnher nf inc-.u required in the dctaclnuei'it may be decreased. Ale-o the posrhilitv ot :uie-

; takes by mutual dia-placement of the rulers avoided.

The invention is not reatrirted to the con- .etructive detail-A which in this specitieation are only indicated by yay ot example. as rari :ne ua'xlilic-ations inar be iuadc in thee-e dfiaili". For example, inl order to facilitate reading the longitudinal correction a inea- 'imlicutiugoY points spiced tiring tape muy he used instead of un a \ljustublc aia:\'ili:1r =,v ruler Si). The end of the measuring 'Lupe would be connected to the point lfl :url uuid (upc would he coiled up rcsiliently ric-ur the end ot the ruler. El' the point Ill) is displ-.iced the nicuf-uringr tupe would he uncoilcd or rolled. up, 5o that :it the ruler li: the diiftuihte muy ulvfnys he read, prcicrzihlf; at the sume spot where also the displacement ol' the ruler L2 for the hitcrul :uljustincnt uuu-.t tulie place.

The Way of niulzingr correctionsl nur? he modified in various ways. For example, ull corrections,` nifty he taken into :recounton the apparatus itsel'` so that no ce1-d system is necezsary. For this purpose the required dota muy he pierced. lor example, on the sector S; also 'inbtead ol' conmuuiczrting the angle ,'51 to the gun the corrected angle l muy he cou'uinuiicut-ed to the gun in which correction the correction ior deflection may already he included. .liso the angle l might he. taken as u correction to W1 by which also [3l need not he signalled to the gun.

The spotting corrections can he 1nechancally imparted. to the subsequent ditta obtained by adjusting the displaceohlc indicators YY1 sind. VF: of Fig. 2.

I chziui: l.t '1. device for laying enti-eil' eruit grs, compr ig two Fit charts piroted together,

one ot' Suid charts hiring' u line thereon er;- tencliire` rudiully from Suid pivot point und graduated to u selected scale and the other of said churts lil-.rinca liuc thereon extending radially from Suid pivot point` zr ruler huuiiur tiro points thereon spaced by the observation point-gun distance to the selected seule and le rehrtire to Suid iirst chur: with one point upon the graduated line oi Suid churt und with the other point engaging" the line ou mid other chart, u Second ruler sliduhle relative to the Second chart und @Adrenalinev at n cous-tuut anule from the line on Suid second churt. und zi third ruler pirotully iuo'fzrhle uhout the point zit which Suid. cluirts ure pivotcil toc-ether.

2. A der-ice i'or laying anti-uir-cra lt guus couipribing' u lit-:ed chui-t havingA u line Q'rzuh uuted to u selected scale. u ruler having two to represent the distance between the ce rvutior, point und the gun to the saine seule, Suid ruler hein;l adapted to he located with one of its indicating points coinciding with the graduation Corresponding to the distance of tl tfrgct 'from the ohscrvution point, and with its 1uclinutiou corrcspondiugv to the angle sub tended :it the ol' errution point between the gun und. the target, u second chart piroted about the zero point' of Seid. graduated line on the lirt chartund hnvingupon it u line :dro )un i said Zero point, the sccoud churt heilig' rr-flied to he eet @o that the line it furries will pues through the second indicating point of ine lirsl; ruler, and u Second. ruler heving two indicating points spaced to represent the height of the target i'roni the .frrouud to the selected scale, and.

more-.hie along and. at un irnuriuhle angle with Said line on the second chart. and with one oi its indicating.; points correpouding with the econd indicating' point of the first rulerA` u'herelri' the inclination of the line in the Second chart to the graduated line ot' the .fixed chart will in "cute the prrralhix angle, und the locution oi the Second indicating point ot the second ruler upon the second chart will Vary radially from the pivot point to correspond with variations in the gunturg'et line.

3. *l device for hiring anti-aircraft guns :is defined in cluin'i .Quid second chart having indications thereon ot various values of the ingle ot super-elevation and time of fiigfjht.

el. .fr device forl laying' anti-aircraft guns :is o lfined in claim said second chart having u puri nioruhie rucliuily along the line thereon und erufluated to the selected. seule. A device lor laying fritti-aircraft guus defined in claim L. un indicator laterally `iiilaccable ou Suid third ruler und. which 'vites upon the sectuid chart the angle oi elevation :it which. 'thel gun Should he set. i device tor laying auti-uircrutt guns ed in clziirn rid second. chart having au indicutor hitch-elly diepluecahle thereu to cooperate with Suid rst chart in 21pplring corrections in lateral direction.

device 'for laying auti-uircratt guus ned in cluiu. "l id seccld chart huring' un ureuute pro) lou prt fided with u Seule, und un indicator laterally diepluceuhle rehitife to Suid iirst chzrrt to cooperate with Suid seule on sind arcuate projection for ind At' Lions iu the purullux hevu-tions.

tween cof l hure signed my nnnie to thisl specicati 

